5.
Read "DTC Status" parameter.
The amount of intake air flow must be inputted to ECM in order to determine the fuel injection quantity. MAPS(Manifold Absolute Pressure) calculates the amount of air indirectly as measuring the pressure inside of intake manifold. This mechanism is alsl called Speed-Density Type.
MAPS transfers analog output signal which is proportional to the change of intake manifold pressure, then, with this signal and RPM, ECM calculates the amount of intake air flow.
MAPS is mounted on surge tank to measure the pressure inside of intake manifold, and it consists of a piezo electric element and hybrid IC which amplifies output signal from the element. A piezo electric element is a sort of a diaphragm using piezo electric effect. One side of the diaphragm is surrounded with vacuum chamber while intake pressure is applied to the other side. Thus, signals are output by the transformation of diagphragm according to the change of pressure inside of intake manifold.
If sensor signal input is higher than 4.88V during 5 sec, ECM sets DTC P0108.
Item | Detecting Condition | Possible Cause |
DTC Strategy | ● Signal check, high | ● Poor connection ● Open or short to power in signal circuit ● Open in ground circuit ● MAPS |
Enable Conditions | ● Engine speed ≤ 30rpm or 5sec after engine start | |
Threshold Value | ● Sensor voltage 〉 4.88V | |
Diagnostic Time | ● 5 sec | |
MIL ON Condition | ● 2 driving cycle |
Pressure [Kpa] | 20 | 46.7 | 101.32 |
Voltag [V] | 0.79 | 1.84 | 4.0 |
Connect scantool to Data Link Connector(DLC).
IG "ON".
Select "Diagnostic Trouble Codes(DTCs)" mode, and then Press F4(DTAL) to check DTC'sinformation from the DTCs menu
Confirm that "DTC Readiness Flag" indicates "Complete". If not, drive the vehicle within conditionsnoted in the freeze frame data or enable conditions noted in the DTC detecting condition.
Read "DTC Status" parameter.
Is parameter displayed "History(Not Present) fault"?
History fault : DTC occurred but has been cleared.
Present fault : DTC is occurring at present time.
▶ Fault is intermittent caused by poor contact in the sensor’s and/or ECM’s connector or wasrepaired and ECM memory was not cleared. Thoroughly check connectors for looseness,poor connection, bending, corrosion, contamination, deterioration, or damage.Repair or replace as necessary and then go to "Verification of Vehicle Repair" procedure.
▶ Go to "Terminal ＆ Connector Inspection" procedure
Many malfunctions in the electrical system are caused by poor harness and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
Has a problem been found?
▶ Repair as necessary and go to "Verification of vehicle Repair" procedure.
▶ Go to " Signal Circuit Inspection " procedure.
Check open in harness.
IG "OFF".
Disconnect MAPS connector.
IG "ON" ＆ ENG "OFF"
Measure voltage between terminal 1 of MAPS harness connector and chassis ground.
Specification : Approx. 5V
Is the measured voltage within specification?
▶ Go to "Check short to battery in harness" as follows.
▶ Repair or replace as necessary and then, go to "Verification of Vehicle Repair" procedure.
Check short to battery in harness.
IG "OFF".
Disconnect MAPS and ECM connector.
Measure resistance between terminal 1 and 2 MAPS harness connector.
Specification : Infinite
Is the measured resistance within specification?
▶ Go to "Ground Circuit Inspection" procedure.
▶ Repair or replace as necessary and then, go to "Verification of Vehicle Repair" procedure.
IG "OFF".
Disconnect MAPS connector.
Measure resistance between terminal 4 of MAPS harness connector and chassis ground.
Specification : Below 1Ω
Is the measured resistance within specification?
▶ Go to "Component Inspection" procedure.
▶ Repair or replace as necessary and then, go to "Verification of Vehicle Repair" procedure.
Check MAPS performance.
IG "OFF".
Connnect CH A probe to terminal 1 of MAPS and CH B probe to terminal 1 of TPS connector.
Warm up the engine to normal operating temperature.
Measure signal waveform of MAPS and TPS together by stepping on and off the accellerator padel.
Specification : Accepatable temperature range : ( 23 ±5 )℃
Pressure [Kpa] | 20 | 46.7 | 101.32 |
Voltag [V] | 0.79 | 1.84 | 4.0 |
Is the measured signal waveform(Comparison response of TPS with MAPS) O.K?
▶ Many malfunctions in the electrical system are caused by poor harness(es) and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage. So, check poor connections and the related circuit between ECM and component thoroughly. Repair as necessary and go to "Verification of Vehicle Repair" procedure.
▶ Substitute with a known - good MAPS and check for proper operation.
▶ If the problem is corrected, replace MAPS and go to "Verification of Vehicle Repair" procedure.
After a repair, it is essential to verify that the fault has been corrected.
Connect scan tool and select "Diagnostic Trouble Codes(DTCs)" mode.
Press F4(DTAL) and confirm that "DTC Readiness Flag" indicates "Complete".
If not, drive the vehicle within conditions noted in the freeze frame data or enable conditions.
Read "DTC Status" parameter.
Is parameter displayed "History(Not Present) fault"?
▶ System performing to specification at this time. Clear the DTC.
▶ Go to the applicable troubleshooting procedure.
